How are they going to adjust the dust amount on the fly when BTC are trading at $650 USD on week and $200 USD the next week? Maybe letting miners decide what to include in the block chain instead of hard coding it into the software perhaps? I thought the whole point of this system was to let the market determine what works and to avoid using some human decree as the law of the land.
It isn't hardcoded it is based on min mandatory tx fee. If a node is set to only relay/mine low priority tx with a min mandatory of 0.1 mBTC (10,000 S) then the dust is 54.3% of that (5430). IF a node is set to relay/mine low priority txs with a min mandatory fee of 0.01 (1,000 S) then the dust is 54.3% of that (543 S). If a node is set to relay/mine low priority txs with a min fee of 0 mBTC (0 S) then the dust is 54.3% of that (0 S).
If miner X won't accept include low priority tx without a fee of Y then that same miner will reject tx which attempt to create transactions that are less than half of Y.